微波萃取-高效液相色谱法测定茶叶中儿茶素和咖啡因

Microwave-Assisted Extraction and HPLC Determination of Catechins and Caffeine in Tea

选用乙酸乙脂为萃取剂，采用微波技术萃取茶叶中表没食子儿茶素、儿茶素、表儿茶素及咖啡因（CAF），用高效液相色谱法（HPLC）法测定。通过正交试验，得到微波萃取四组分总量的最佳条件为萃取温度100℃，萃取时间10min，浸润水与乙酸乙酯体积比1：8，其相对标准偏差和回收率分别为2．1％～2．4％和54．2％～100．1％。

Caffeine and 3 catechins in tea were separated hy microwave-assisted extraction using ethyl acetate as solvent, and their contents were determined in the extract. The operating conditions of extraction were studied by using the method of orthogonal experimental designing and optimum conditions found were as follows： （1） temp. of extraction： 100℃; （2） time of extraction： 10 min; （3） extraction solvent： mixture of ethyl acetate and water （mixed in the ratio of 1 to 8）. Precision and recovery of the method by using microwave assisted extraction were tested, and values of RSD＇s （n=5） and recovery found were in the ranges of 2.1%-2.4% and 54.2%-100.1% respectively.